Imaging Core B: Project Summary The DDBTRCC Imaging Core B is designed to provide our Research Base investigators. equipment for and instruction and assistance in use of multiple levels of classical and cutting edge fluorescence microscopy and electron microscopy (EM) techniques for study of the physiology and cell biology of GI track epithelial cells at the level of organs, tissues, cell models, and sub-cellular organelles. These include confocal and multiphoton confocal microscopy with applications for intracellular pH and Ca2+ measurements and protein trafficking at a single cell level, FRET microscopy for detection of protein-protein interactions in in vitro and in vivo models, FRAP microscopy for monitoring the changes in protein mobility due to the changes in protein complexes, and META spectral imaging for more than 4 fluorophores. The Core also offers ratio-excitation imaging systems of single cells (microscope/camera based) or groups of cells (fluorimeter) for quantitative measurements of ion concentrations in polarized epithelial cells or in non-polarized cells and a cooled CCD camera for documenting histologic slides. Core B has expanded the repertoire of microscopy imaging techniques by being awarded a SIG (collaboration with JHU Imaging Core) to bring super resolution technology to JHU. Additionally, we developed a partnership with industry and opened an Olympus Equipment Demonstration Center, to provide access to Center members of advanced Olympus microscopy equipment which already includes confocal-in-a- box technology for long time (days) live tissue imaging and advanced TIRF microscopy. Core B also assists DDBTRCC investigators in preparation of intestine, liver, pancreas, and kidney for EM imaging and data interpretation. Since the Center was funded in 2011, the Imaging Core has provided services to 44 current and previous Center investigators, 37 Members and 7 Associate Members and contributed to 76 publications.